The invention relates generally to automotive accessories. Over-the-road trailers often include replaceable sealed plastic taillights that pop into a rubber gasket on a round hole in the trailer frame. An internal electrical cable has a plug that is connected to the back/inside of the sealed taillight. In some embodiments, the electrical cable plug includes three wires: ground, running-light power, and brake-light power. The outer lens face (usually transparent red plastic having an inside face with an array of corner reflectors) is typically sealed to the inside/back portion.
Truckers are often faced with the need for 12-volt power at the back of the trailer, but no power jacks are available on most trailers. Some folks splice wires to the internal electrical cable and try to run the spliced wired through or around the rubber gasket that holds the taillight to the trailer. This runs the risk of shorting the wires to the sheet-metal frame surrounding the rubber gasket. In addition, the splices tend to corrode and do not provide reliable long-term electrical connectivity.
Accordingly, there is a need in the art for improved methods and devices for supplying power to an external electrical connection on a vehicle.